Directions:

Combine sugar, cornstarch and salt in a medium saucepan. Slowly stir in water. Cook over medium heat, stirring constantly, until mixture is thick and bubbly. Remove from heat.

Beat egg yolks and gradually add a cup of the hot mixture to the egg yolks.

Stir egg mixture back into the mixture in the saucepan and cook over low heat for 2 minutes, stirring constantly.

Add butter, lemon juice and lemon zest. Stir until blended. Pour filling into the cooled pie shell and set aside to cool.

Whip egg whites with cream of tartar until foamy white. Gradually add sugar and continue whipping until meringue forms stiff peaks. Spoon meringue over pie filling using a spatula to form small uniform peaks.